231.

Which of the following statement(s) regarding energy flow is/are false?

I. The detritus food chain begins with dead organic matter.

II. In aquatic ecosystem, detritus food chain is the major conduit for energy flow.

III. In terrestrial ecosystem a larger fraction of energy flows through grazing food chain.

IV. Producers belong to the first trophic level of the food chain.

• II and III only

• III and IV only

• I and IV only

• I and II only

• I and II only

Match the following.

Column I	Column II
A. Earthworm	1. Catabolism
B. Bacterial and fungal enzymes	2. Breaks down detritus into smaller particles
C. Accumulation of dark coloured amorphous substance	3. Detritivores
D. Fragmentation	4. Humus

• (A) - (3), (B) - (2), (C) - (4), (D) - (1)

• (A) - (3), (B) - (l), (C) - (4), (D) - (2)

• (A) - (2), (B) - (1), (C) - (4), (D) - (3),

• (A) - (2), (B) - (3), (C) - (4), (D) - (1)

• (A) - (2), (B) - (3), (C) - (4), (D) - (1)

The first trophic level in an ecosystem consists of

• Primary producers

• Primary consumers

• Secondary producers

• Secondary consumers

• Secondary consumers

Select the correct statement

• Phosphorus cycle is an example of gaseous nutrient cycle

• The pyramid of biomass in sea is generally inverted

• By the process of humification, soluble inorganic nutrients go down into the soil horizon

• A given organism may not occupy more than one trophic level simultaneously

• A given organism may not occupy more than one trophic level simultaneously

The rate of biomass production and the rate of production of organic matter during photosynthesis are called respectively

• Total productivity, primary production

• Gross primary productivity, gross secondary productivity

• Net primary productivity, secondary productivity

• Net productivity, gross secondary productivity

• Net productivity, gross secondary productivity

The gross primary productivity of an ecosystem is 170 tons organic matter and amount used in respiration is 50 tons. Calculate the net primary productivity of the ecosystem.

• 120 tons

• 100 tons

• 70 tons

• 12 tons

• 12 tons

The pioneer species in xerarch and hydrarch succession are respectively

• Lichens and sedges

• Phytoplanktons and sedges

• Lichens and zooplanktons

• Lichens and phytoplanktons

• Lichens and phytoplanktons

Identify the ecologist from the given hints

(i) Has carried out long-term ecosystem experiments using outdoor plots

(ii) In his experiments he showed that increased diversity contributed to higher productivity

• Ahmed Khan

• David Tilman

• Stanley Choen

• Ernest Chain

• Ernest Chain

Which of the following ecological pyramids is generally inverted?

• Pyramid of energy

• Pyramid of biomass in a forest

• Pyramid of biomass in a sea

• Pyramid of numbers in grassland